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MRP Pop Quiz

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MRP Pop Quiz
Posted by dehusman on Friday, January 20, 2017 8:12 PM

Question 2 gave me pause.  It is ever so close, but just not quite technically right (possibly pun intended).

The first part is only true if there are yard limits in effect.  It kinda implies in the discussion of question one that there are yard limits at every yard (not correct) and question two continues that assumption.  If yard limits are not in effect then the entire answer is wrong.  If there are no yard limits (for example if there is CTC) then the trains go through the yard at track speed.  If the track speed is 60 mph and a train has clear signals it can go 60.  If there is CTC then the discussion about the first class train is moot.

Also the discussion about the "rights" of the first class train.  Technically it doesn't have "right", it has "superiority".  Picky picky I know, until you start reading the rules and then things won't match up, because they will be talking about superiority. 

Superiority is granted by by right, class and direction.  Class and direction are conferred by the timetable and right is conferred by train order.  If its a first class train it has superiority by direction.  An inferior train has to clear its schedule because of its class and direction, not because it has "right".

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by IRONROOSTER on Saturday, January 21, 2017 12:44 PM

Doesn't some of this depend on the railroad?  IIRC each railroad has it's own rules, granted there is a lot of similarity, but still..  Plus the railroad can designate special rules for a particular location.

Paul

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Posted by dehusman on Saturday, January 21, 2017 4:51 PM

IRONROOSTER

Doesn't some of this depend on the railroad?  IIRC each railroad has it's own rules, granted there is a lot of similarity, but still..  Plus the railroad can designate special rules for a particular location.

Yes there are variations in the rules.  Having said that, superiority of trains has been consistent in every rule book I have read from the 1890s (or earlier) thru 1985 or so when TT&TO was replaced by track warrants.    Yard limits do vary slightly (some require 2nd class trains to be cleared, some older and some newer require trains to "give way" rather than clear, and the PRR and a couple eastern roads required trains to get permission form the yardmaster, most didn't), however one thing that is absolutely consistent is that yard limits rules only apply where yard limits are in effect.  If yard limits are not in effect then the yard limit rules do not apply.  If you want to operate by yard limits rules you have to have yard limits in effect.  Under the majority of rule books I have read mean you have to have yard limit signs and or yard limits noted in the timetable.  I have glued a yard limit sign to the fascia on some of my layouts since my railroad used an oval rather than the "V" yard limit sign.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by BRAKIE on Sunday, January 22, 2017 12:08 PM

I don't know of any engineer in his right mind that would barrel through a yard at 60 per since that would be suicidal at best because the yard switches may not be lined for his move and the yard switcher would be working blocking the track plus other yard moves that may be taking place.

However, he would run 60 per on the yard's bypass track since there is limited access by the yard crew and he knows the switches is lined for his move..

Larry

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Posted by dehusman on Sunday, January 22, 2017 4:12 PM

Remember, we are talking about the MAIN TRACK (the track that goes through yards and between stations by definition) and whether there are YARD LIMITS or CTC in effect on that main track.  If you are in CTC and you have clear signals all the switches will be lined for your movement and you may proceed at the maximum authorized speed, if that is 60 then you can go 60.  If you are in yard limits, with a block signal system and the rules allow you to proceed on signal indication if the signal is better than approach, and the signals are clear, all the switches will be lined for your movement, then you can proceed at maximum authorized speed.  If that is 60 then you can go 60.

If its CTC then any train or engine that wants to enter the main track has to do it with either signal indication or verbal instructions of the dispatcher.  Either way, opening the switch will drop the signals.  If its ABS yard limits then the crew has to open teh switch and wait five minutes, once again dropping the signals.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by BRAKIE on Sunday, January 22, 2017 8:26 PM

dehusman
Remember, we are talking about the MAIN TRACK (the track that goes through yards and between stations by definition) and whether there are YARD LIMITS or CTC in effect on that main track.

Yes,the bypass track as we called it when I worked the rails.The bypass track is located on the outside edge of the yard and like you stated  is controlled by either a tower or  dispatcher by CTC and yard crew don't use the bypass without permision.

Did you know if a through freight  is routed through the yard  the speed  must be slow enough to respond to a hand signal or radio command from a brakeman riding the steps of the lead engine watching for reversed switches and any opposing yard move. I even seen NS do this at Bellevue. I suppose it more important today because of the R/C yard units.

Larry

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Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

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Posted by dehusman on Sunday, January 22, 2017 8:34 PM

BRAKIE
Did you know if a through freight is routed through the yard the speed must be slow enough to respond to a hand signal or radio command from a brakeman riding the steps of the lead engine watching for reversed switches and any opposing yard move.

Once the train leaves the main track and is actually in the yard, it is no longer operating by yard limit rules, it is operating on "track other than a main track", which is normally covered by rule 105.  It generally requires operating at a speed that will allow stopping short of (or within half the range of vision of) an obstruction, equipment, switch not properly lined. The max speed will normally be in the timetable (typically in the 5-10 mph range).

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by rrinker on Monday, January 23, 2017 7:02 AM

 So did Tony have that wrong in MRP 2017, or is that just a rule difference for NKP? He had that any yard crews had to clear the main based on the schedule of any first class trains, all others had to operate at restricted speed within yard limits, prepared to stop (as in rule 105). Or is this a model simplification where for space reasons you often don't have a main AND a bypass track?

                                     --Randy

 


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Posted by dehusman on Monday, January 23, 2017 9:38 AM

rrinker
So did Tony have that wrong in MRP 2017, or is that just a rule difference for NKP?

No and no (with caveats).

The issue is that the presence of a "yard" does not create yard limits.  Yard limits is another way of granting authority on the main track, just like the timetable, train orders, track warrants, CTC, etc.  You can have yard limits with no yard and you can have a yard with no yard limits.  His description of clearing the superior trains is accurate if there are yard limits, he just didn't explicitly say in his answer #2 that there wer yard limits.  It was  assumed.

With regard to the use of "rights" vs. "superiority", yes I know its picky, but its that type of mixing things that causes a lot of the confusion in rules discussion. For example we are headed down that path already.

   Or is this a model simplification where for space reasons you often don't have a main AND a bypass track?

There is no such thing as a "bypass" track in the rules.  Its either a main track, a siding or track other than a main track.  Probably the "bypass track" is actually a main track in the timetable.  For example, Ogden UT on the UP has a "by pass" track around Riverdale Yard and it is shown in the timetable as "Main Track 3 (By Pass)" and is a CTC main track with cab signals while main tracks 1 and 2 are just CTC.  While there are two yards there (Ogden and Riverdale), neither one is in yard limits.  In reality very few prototype yards have a "bypass" track if they are a main track then all the same rules apply that would on any other main track.

Railroad rules are really pretty simple.  Where modelers get messed up is they invariably want to make some sort of special case or they compare rules from different railroads, different eras, different locations and even different countries.  The hard part about railroad rules is context.  When you read the rules sitting in your living room they don't make that much sense, but if you are standing at the switch, they are obvious.  Also the rules have to be taken as a body, a single rule taken out of context may be confusing, but when combined with related rules are clear.

Dave H. Painted side goes up. My website : wnbranch.com

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